This invention relates to irrigation pump systems, particularly to devices used to irrigate surgical sites during medical procedures.
Devices that deliver irrigating fluid to an irrigation site are necessary in a variety of medical and dental procedures. For example, laparoscopic, arthroscopic and hysteroscopic procedures require sufficient volumes of irrigation fluid to be delivered to the surgical site in order to maintain tamponade, isolate bleeders and to generally clear the surgical area. Laparoscopic procedures involve incisions to the abdominal cavity and include appendectomies, cholecystectcomy (incision of the gall bladder) and treatment of ectopic pregnancies. Hysteroscopic procedures involve inspection of the uterine cavity and include procedures that remove abnormal tissue from the uterus such as a biopsy or a myomectomy. Arthroscopic procedures are typically performed by an orthopedic surgeon and involve irrigation, distension and inspection of the joints such as at the knee, shoulder, elbow or ankle. Such arthroscopic procedures include synovectomy, meniscectomy or repair of the anterior cruciate ligament.
During these various medical procedures, it is generally useful for the surgeon to keep tissue that surrounds the surgical site out of the way by injecting solutions such as saline, glycine or lactated ringer""s solution into the subject area. As each procedure requires different volumes of fluid delivered at various pressures, it would be useful for health care providers to have a single pump that could be adapted to deliver the appropriate irrigation for various procedures.
Another important aspect of medical irrigation pumps is sterility. Fluid that enters the body during a surgical procedure must be maintained sterile. However, efforts to maintain sterility become complicated when expensive hardware, such as a pump, is used. Sterility is more easily and assuredly maintained when medical devices that carry irrigant fluid to the body can be discarded after each use. It is possible to provide a medical irrigation pump that utilizes a permanent non-sterile pump motor that can generate pumping action in a sterile fluid pathway that is disposable and detachable from the permanent motor hardware.
U.S. Pat. No. 3,927,955 (Spinosa et al.) discloses a medical cassette pump that utilizes peristaltic pumping action to pump fluid through a sterilized fluid path. The pump consists of a non-sterile permanent electric motor that rotates planetary rollers. The rollers engage the exterior surface of flexible sterilized tubing that is maintained around the circular outer edge of a disposable cassette. As the rollers compress the tubing against the edge of the cassette, fluid pumping action is provided. The cassette and tubing are removable from the rollers and motor and may be discarded and replaced with a new sterile cassette and tube for each use.
U.S. Pat. No. 4,635,621 (Atkinson) discloses a lavage pump system that utilizes a permanent electric motor that engages a sterile disposable pumping unit. A linear reciprocating electric motor releasably engages the end of a piston rod that is part of the piston/cylinder disposable pump. The replaceable sterile lavage pump slides into a compartment that is adjacent the electric motor so that the motor and piston rod can be maintained in a working relationship. It would be highly desirable to provide a medical pump that could drive a wide variety of sterile replaceable pumping mechanisms to serve the many medical procedures that health care providers must perform.
This invention relates to fluid pumps used in medical procedures that employ a permanent non-sterile pump motor which interfaces with a sterile and disposable pumping mechanism and fluid pathway. This pump system utilizes a sophisticated electronic controller that powers a rotary electric motor. The controller and motor are provided with a holder that is designed to receive one of several disposable and sterile pumping mechanisms or bodies that join and become part of a sterile fluid pathway through which the irrigation fluid travels. Sterile irrigation fluid may be supplied from irrigation bags or bottles to the pump body through flexible tubing. After the irrigation fluid is pumped through a sterile pump body it travels out through flexible tubing to an irrigation handpiece that is appropriate for the procedure being performed. All components of the fluid pathway (irrigant bags, pump body, handpiece and flexible tubing that joins them) are sterile, disposable single use items.
Several distinctly configured pumping mechanisms or pump bodies can be used with the motor/controller system. A centrifugal pump utilizing a spinning impeller to create a controlled fluid pressure and flow rate is used in laparoscopic, hysteroscopic and arthroscopic procedures. However, as each procedure requires a specific fluid delivery pressure and rate, three different pump types utilizing respectively sized impellers are used. Other pumping mechanisms can also be used with the controller; these pumping mechanisms can also be configured to generate fluid outputs which are specifically suited for a particular medical procedure.
The permanent controller is capable of receiving the various disposable pump body types in a specially-shaped holder attached to the bottom of the controller. More particularly, a frame hinged along the back edge of the bottom of the controller is opened and tilted downward to receive the disposable pump body. Although each pump body type has a different internal configuration suitable for its intended procedure, the external dimensions of all pump body types are the same so that each pump body will fit in the controller frame. Once the pump body has been placed into the lowered frame, the frame is closed upward and latched so that the pump body engages the controller and drive motor.
The pump body interfaces with the controller in several ways. First, the pump motor engages the pump drive member of the disposable pump. A paddle attached to the end of the rotating motor shaft catches and rotates a pump drive rod that protrudes through the top of the pump body. Thereafter, when the electric motor rotates, the rotating paddle will cause the pumping mechanism to rotate, in turn, generating a fluid flow through the given pump body and delivering a fluid output at a controlled pressure. The fluid delivery rate and pressure can be changed, within limits determined by the pump body design, by increasing or decreasing the rotational speed of the motor.
The disposable pump body interfaces with the controller in a second manner that enables the controller to automatically identify which type of pump body has been inserted and, based on that identification, to set an initial default motor speed and upper and lower motor speed limits to the appropriate levels. This identification is accomplished by switches located at the interface between the controller and the pump body, switches detect which pump body type has been installed in the controller. In particular, small bumps molded into the top of each pump body in a pattern unique to each pump body type engage an array of switches which is located on the underside of the controller. When the hinged frame is closed to engage the pump body with the controller, the bumps operate the switches in a predetermined pattern unique to that particular pump body. The pattern of depressed switches is used to retrieve identification information and default settings from a non-volatile storage located in the controller. The retrieved information is used to drive an LED display that notifies the user as to which pump body type has been installed by displaying a medical procedure type that corresponds with the installed pump body type (for example, a laparoscopic procedure, hysteroscopic procedure, arthroscopic procedure, etc.) As a safety feature, the user must confirm that the displayed procedure type is the intended procedure by pressing a confirmation button before the pump will start. Upon confirmation by the user, the controller selects a default motor speed that will generate an appropriate fluid pressure and subsequent flow rate for the given procedure. Upper and lower speed limits are also retrieved from the internal storage to set the maximum and minimum fluid pressures, respectively.
A user can easily set-up and operate the desired irrigation pump, with a minimum of preparation time when using this system. Upon selecting the appropriate pump body type for the desired medical procedure, the user simply joins a reservoir of irrigation fluid such as saline, lactated ringer""s or glycine to the pump body via flexible tubing. The reservoir is mounted above the pump body to promote fluid flow by gravity into the pump. The user may also install an appropriate irrigation handpiece to the pump outlet via flexible tubing. The flexible tubing set may be provided with a preconnect end fitting for quick connection to medical devices which attach to the patient. To install the pump body into the controller, the user releases a catch on the front of the frame which is hinged at the opposite side and swings downward in the front. The user then inserts the pump body into the frame.
While resting in the inclined open frame, the pump body fills with fluid and air is automatically purged from the pump body to prime the pump. The angled position of the pump body in the open frame insures that any air in the pump body is driven out as the pump body fills with fluid due to the relative positions of the fluid inlet and outlet lines. Specifically, the outlet line which is located at the bottom of the pump body at a position near the frame hinge is connected to a channel molded into the interior of the pump body which insures that the fluid outlet is located at the top of the pump body. Therefore, fluid entering through the inlet line at the center of the pump body (carried by gravity) fills the pump body and air bubbles are pushed to the top of the container and are automatically purged out through the outlet.
After priming is complete, the user closes the frame, engaging the pump with the paddle which is attached to the shaft of the electric motor in the controller. The controller automatically recognizes the type of pump body installed, generates a display indicating the procedure for which the pump body was designed and waits for the user to confirm the procedure. After confirmation, the controller automatically registers a maximum, minimum and default pump pressure and the user may begin the procedure by pressing another controller button to start the controller motor. Once the pump has started, the user may adjust the fluid pressure delivered by the pump at the control panel of the controller by appropriately pressing increase and decrease buttons or may stop the electric motor by pressing a stop button.
It is among the general objects of this invention to provide a medical irrigation pump system that utilizes permanent non-sterile pump motor hardware and a replaceable pump mechanism that is sterile and disposable along with all the components that comprise the fluid pathway.
Another object of the invention is to provide a medical irrigation pump system that can be adapted to be used in various medical procedures requiring various irrigation flow and pressures.
Another object of the invention is to provide a medical irrigation pump system that utilizes a controller that is capable of recognizing and identifying different pumping mechanisms that have been installed for use in various medical procedures.
It is a further object of the invention to provide a pump controller that upon identifying which type of pump mechanism has been installed, automatically sets an appropriate motor speed to drive the pump mechanism safely for the intended procedure.
It is a further object of the invention to provide a pump motor controller that can be adjusted by the user to increase the pump pressure of the irrigation fluid by regulating the motor speed.
It is another object of the invention to provide a medical irrigation pump system that permits quick and easy priming of the installed pump mechanism.
It is another object of the invention to provide various pump mechanisms, suitable for various medical procedures that are easily connectible to conventional irrigation fluid reservoirs and irrigation handpiece assemblies.